Re: AVD-3878 H.248.SDPMapper: "m="-line with multiple transport elements

Hello Albrecht,

Yes that is correct.

Regards, Christian

Schwarz Albrecht wrote:
> Hello Christian, Tommy,
> got a question for clarification:
> the highlighted "m="-line below, with multiple transport elements, is 
> syntactically not possible with RFC 4566 (2327), but feasible in H.248 
> due to the alternative option in 7.1.8.1.1.1/H.248.1.
> Right?
> Thanks,
> Albrecht
> ____H.248.1 _____________________________________________________
>
>
>           7.1.8.1.1 Specific syntax for H.248 text encoding
>
>
>             7.1.8.1.1.1 Rules
>
> When text encoding the protocol, the descriptors consist of session 
> descriptions as defined in SDP ([IETF RFC 2327]). In session 
> descriptions sent from the MG to the MGC, the SDP must comply with 
> [IETF RFC 2327]. In session descriptions sent from the MGC to the MG, 
> the following exceptions to the syntax of [IETF RFC 2327] are allowed:
>
> • the "s = ", "t = " and "o = " lines are optional;
>
> • the use of CHOOSE is allowed in place of a single parameter value; and
>
> • the use of alternatives is allowed in place of a single parameter value.
>
> ...
> ____ AVD-3878 _____________________________________________________
> http://wftp3.itu.int/av-arch/avc-site/2009-2012/1003_Sha/AVD-3878.zip
>
>
>       6.1.2 Relationship with the H.248 Reserve Value concept
>
> SDPCapNeg also allows the ability to specify alternatives (via the use 
> of “|”) in configuration lists. The MGC can also provide this 
> functionality via the use of over specified property values (or SDP 
> parameters as per ITU-T H.248.39). Over specification of properties is 
> equivalent to providing alternatives which effectively is a “or” 
> function in the same way as “|”.
>
> For example, given the following Revised Offer/Answer SDP:
>
> v=0
>
>       o=- 25678 753849 IN IP4 192.0.2.1 
>       s=  
>       c=IN IP4 192.0.2.1 
>       t=0 0 
>       m=audio 53456 RTP/AVPF 0 18  
>       a=tcap:1 RTP/AVPF RTP/AVP RTP/SAVP RTP/SAVPF 
>       a=pcfg:1 t=2|1 a=1 
>
> The MGC would construct the following SDP for the first H.248 Group:
>
> v=0
>
>       o=- 25678 753849 IN IP4 192.0.2.1 
>       s=  
>       c=IN IP4 192.0.2.1 
>       t=0 0 
>       m=audio 53456 RTP/AVP RTP/AVPF 0 18  
>